First edition of this monograph on the freshwater molluscs of Brazil, the first work devoted to Brazilian shells, and one of several publications resulting from Spix and Martius' expedition to Brazil from 1817 to 1820. The expedition was under the aegis of the King of Bavaria, Maximilian Joseph I. 'His plans for sending scientific explorers to South America were realized in 1817, when an Austrian expedition was sent to Brazil. Martius and several other Bavarian scientists, including his companion, the zoologist Spix, went along. They left Trieste on 2 April 1817 and returned to Munich in December 1820' (DSB). 'Spix and Martius were the first European scientists to visit the Amazon after La Condamine. Their collections ... provided material for a vast number of works by other scientists. Spix himself was occupied entirely with publishing his findings after his return to Munich... Weakened by the fevers that he had suffered on his voyage, he died [in 1826], leaving other zoologists, including Louis Agassiz, to complete the publication of his works' (ibid.). For this volume the descriptions were provided by J.A. Wagner. It was edited by Paula von Schrank and Martius. Borba de Moraes II 280; Nissen ZBI, 3954